JP3337574B2 - Positioning method of discharge torch electrode body in wire bonding apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire bonding apparatus in which a ball portion is formed at a lower end of a metal wire inserted into a capillary tool by a discharge between the lower end and a discharge tip of a discharge torch electrode body. The present invention also relates to a method for determining a relative position of a discharge tip of a discharge torch electrode body with respect to a capillary tool in a wire bonding apparatus so as to press-bond the ball portion to a bonding portion such as a semiconductor chip.

[0002]

2. Description of the Related Art Generally, as described above, a wire bonding apparatus provided with a discharge torch electrode body for forming a ball portion at a lower end of a metal wire uses a cabillary tool having a metal wire inserted therein, and a wire bonding apparatus. The movable torch is attached to the tip of a horn that is pivotally attached to the movable head so that the torch electrode body for discharging the metal wire is fixed to the movable head immovably up and down. When the capillary tool is moved upward, a discharge is generated between the discharge tip of the discharge torch electrode body and the lower end of the metal wire.

[0003]

By the way, in this type of wire bonding apparatus, as described above, the discharge torch electrode body is fixedly mounted so as not to move up and down, while the capillary tool in which the metal wire is inserted is used. Because it moves up and down, when attaching the discharge torch electrode body, when the capillary tool is raised, between the lower end of the metal wire inserted therethrough and the discharge tip of the discharge torch electrode body. In a state where the predetermined discharge interval is maintained, and when the capillary tool is moved down, the discharge tip of the discharge torch electrode body does not contact with either the capillary tool or the horn and must be immovably positioned. No.

However, in the conventional wire bonding apparatus, when the discharge torch electrode body is attached, the relative position of the discharge tip with respect to the capillary tool is determined by an operator's eye measurement. In mounting the discharge torch electrode body, the discharge torch electrode body is fixed immovably in a state where the relative position of the discharge tip to the capillary tool is visually determined, so that it takes a lot of trouble. Not only is required, but also the discharge interval between the discharge tip of the discharge torch electrode body and the lower end of the metal wire inserted into the capillary tool varies greatly, making it difficult to control the voltage during discharge. There was a problem to say.

The present invention provides a method for positioning the relative position of the discharge tip with respect to the capillary tool when mounting the discharge torch electrode body, in a very simple and accurate manner. It is an issue.

[0006]

In order to achieve this technical object, the present invention provides a capillary tool attached to the tip of a horn pivotally movable up and down on a movable head in a wire bonding apparatus, and a lower end of a capillary tool. In a state in which the capillary tool is moved downward so as to abut against the member, the capillary tool is provided with a cylindrical mold having a positioning recess on the outer periphery, and the cure is performed on both the lower surface of the horn and the upper surface of the work member. Then, the discharge torch electrode body, which is attached to the movable head so as to be position-adjustable, is inserted into the positioning recess on the outer periphery of the treatment, and the discharge torch electrode body is inserted in this state. Thus, the discharge torch electrode body is fixed so that the position cannot be adjusted. "

[0007]

[Operation] As described above, while the cylindrical tool is fitted to the capillary tool which has moved downward with respect to the work member,
The discharge torch electrode body, which is mounted so as to be position-adjustable with respect to the movable head, is inserted into the positioning recess provided on the outer periphery of the above-mentioned specific condition, and in this state, the discharge torch electrode body is adjusted in position. By immobilizing the discharge torch electrode body, a predetermined discharge gap is maintained between the discharge tip and the lower end of the metal wire inserted into the capillary tool, and the discharge tip is provided with a capillary tool and The positioning can be reliably performed in a relative relationship in a state of not contacting any of the horns.

[0008]

In other words, the present invention uses
Since the relative position of the discharge torch electrode body to the capillary tool is also determined, the positioning is extremely simple compared to the conventional method of positioning by visual measurement, greatly reducing the number of steps required. In addition, the discharge gap between the discharge tip of the discharge torch electrode body and the lower end of the metal wire inserted into the capillary tool can be reduced, and the voltage management during discharge can be easily performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 denotes a movable head in a wire bonding apparatus, reference numeral 2 denotes a horn configured in an elongated tapered shape, and the horn 2 moves up and down by a pin 3 with respect to the movable head 1. A capillary tool 4 is attached to a tip of the robot, and a metal wire 5 such as gold is inserted into the capillary tool 4.

Reference numeral 6 denotes a discharge torch electrode body. The discharge torch electrode body 6 is attached to the movable head 1 by a bracket 8 which is adjustably attached to the movable head 1 with an adjustment bolt 7. The relative position between the discharge tip 6a and the capillary tool 4 in the discharge torch electrode body 6 can be freely adjusted by, for example, being adjustable and fastened with the bolt 9, and the both adjustment bolts can be adjusted. It is attached so that it can be fixed in its adjustment position by firmly tightening 7, 9.

As is well known in the art, the wire bonding apparatus has a lower end of a metal wire 5 inserted into the capillary tool 4 and a discharge tip 6a of the torch electrode body 6 for discharging. When the ball portion is formed by electric discharge during the period, the capillary tool 4 is moved downward by the downward rotation of the horn 2, and the ball portion of the metal wire 5 is bonded to the first bonding member of the work member 10 such as a lead frame or a semiconductor chip. Then, the capillary tool 4 moves to the second bonding portion after ascending, and moves down, thereby joining the middle of the metal wire 5 to the second bonding portion. By repeatedly moving up while cutting the metal wire 5 and returning to the original state, We perform wire bonding.

When mounting the discharge torch electrode body 6 while maintaining a predetermined relative position between the discharge tip 6a and the capillary tool 4, the capillary tool 4 must first be As shown in FIG. 3 to FIG. 5, a fixing member 11 having a cylindrical shape, an upper end surface formed into a conical surface 11a, and a positioning recess 11b provided on an outer peripheral surface is fitted. Thereafter, the lower end of the horn 2 is rotated downward, so that the lower end of the capillary tool 4 is moved to the reference surface 12 such as a second bonding portion of the work member 10.
It moves down so as to contact with.

At this time, the length dimension L in the control 11 is set such that the lower end surface 11c of the control 11 contacts the reference surface and the upper edge 11d contacts the lower surface of the horn 2. Next, the discharge torch electrode body 6 is placed under the condition that both adjusting bolts 7 and 9 are loosened.
a is fitted into the positioning recess 11b of the fixing device 11, and in this state, the two adjusting bolts 7, 9
Is firmly tightened to fix the position in the above-mentioned state so that the position cannot be adjusted.

In this case, the lower end of the metal wire 5 inserted into the positioning recess 11b on the outer peripheral surface of the fixing member 11 when the capillary tool 4 is raised and the discharge tip of the discharge torch electrode body 6 are moved. A predetermined gap between the discharge tip 6a of the discharge torch electrode body 6 and both the capillary tool 4 and the horn 2 when the capillary tool 4 is moved downward while maintaining a predetermined discharge interval between the capillary tool 4 and the horn 2. By providing the discharge torch electrode body 6 at a position where S and T can be obtained,
A state in which a predetermined discharge gap is maintained between the discharge tip 6a and the lower end of the metal wire 5 inserted into the capillary tool 4, and the discharge tip 6a does not contact either the capillary tool 4 or the horn 2. Positioning can be performed reliably in a relative relationship.

By forming the upper end surface of the fixing unit 11 into a conical surface 11a, the upper end edge 11d
Can be brought into contact with the base of the capillary tool 4 on the lower surface of the tapered horn 2 as shown in FIG. 7, so that the positioning can be performed more accurately.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a wire bonding apparatus.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged perspective view showing a cure used in the method of the present invention.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 illustrates the method of the present invention.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

[Explanation of symbols]

Reference Signs List 1 movable head of wire bonding apparatus 2 horn 3 pin 4 capillary tool 5 metal wire 6 discharge torch electrode body 6a discharge tip of discharge torch electrode body 8 bracket 7, 9 adjusting bolt 10 work member 11 cure 11a conical surface 11b Positioning recess 11c Lower edge 11d Upper edge 11d

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60

Claims (1)

(57) [Claims] 1. A capillary tool attached to a tip of a horn pivotally attached to a movable head in a wire bonding apparatus so as to be vertically movable, and moved downward so that a lower end thereof contacts a work member. , A cylindrical mold having a positioning recess on the outer periphery, is fitted so that the cure contacts both the lower surface of the horn and the upper surface of the work member, and then with respect to the movable head. Inserting the discharge torch electrode body to be position-adjustable by inserting the discharge tip into the positioning recess on the outer periphery of the above-mentioned specific condition, and fixing the discharge torch electrode body so that the position cannot be adjusted in this state. A method for positioning a discharge torch electrode body in a wire bonding apparatus.